It quoted three people as saying that the decision is not final, but that Trump appears to have settled on Rubio, a loyalist whom Trump passed over as his vice presidential running mate, AFP reported.
Rubio has been consistently named over the last week as one of the frontrunners to head US diplomacy, along with the abrasive former ambassador to Germany, Ric Grenell.
Asked if he was destined for a senior cabinet job, Rubio told CNN last week, “I always am interested in serving this country.”
The nomination of the hawkish congressman, who has Cuban heritage, would cap a remarkable turnaround in his relations with Trump.
In 2016, when they were competing for the Republican presidential nomination, Rubio called Trump a “con artist” and the “most vulgar person to ever aspire to the presidency.”
Born to Cuban immigrants in Miami, he graduated with a political science degree from the University of Florida in 1993.
He was elected to the US Senate in 2010 with his campaign buoyed by the Tea Party, a far-right contingent of Republicans that coalesced in the aftermath of Barack Obama’s election as president.